In one corner of Paris, they filed solemnly into church. In another, they scrambled for cover.

Just as thousands of Parisians were calmly gathering last night at Notre Dame for a special Mass in memory of Friday's victims, panic broke out in the Place de la Republique as gunshots were reported. It later transpired that it was a false alarm.

The two scenes, shortly before 7pm, vividly illustrated the twin reactions to Friday's terror in this city on the edge: panic - and defiance.

In the square, one man hid in a cellar while a television reporter making a live broadcast dived for shelter behind a van; police evacuated the area, helicopters whirred overhead.

At the cathedral, everybody's bag was searched and jittery gendarmes patrolled the grounds with guns, muttering into walkie-talkies. But the service went on, the heat of hundreds of candles warming up the front row.

Notre Dame's pews were full and 3,000 more worshippers had to stand outside as the capital came together to remember its dead and to sing in their name.

"Bind us together in the peace of your love, O Lord," the 1,500-strong congregation inside intoned.

Outside, the crowd sang too. The 13-tonne bell of the south tower, which usually sounds only for Christmas and other major holidays, rang out.

Then the Archbishop, hands clasped in prayer, addressed the topic on everybody's minds: "As we face this blind barbarism, each breach of our firm convictions will be a victory for our aggressors," he said.

Determination

"Trust in the human being and his dignity is the only way to respond to savagery. The Lord's greatness is not shown by beheading people but by working towards the respect of humanity."

It was a message his congregation - and many thousands of Parisians - had already taken to heart. Two hours before the Mass, hundreds were already queueing outside Notre Dame.

Marie Francoise (72) had one foot in a cast after an operation but still made the two-hour round trip by bus to the cathedral, to stand in line. "When I saw those images on TV, I knew I had to go out," she said. "This is an exceptional day."

Patricia Pettitt, whose son's girlfriend was still in hospital recovering from the Bataclan attack, came to pray too.

The Englishwoman has lived here 40 years and considers herself a Parisian.

"We are angry," she said. "But we cannot do anything about it. I go [to church] every Sunday. But it is special today because of all the people who have died."

Valerie Carteron usually only comes to Notre Dame at Christmas, but she made an exception yesterday.

"Notre Dame is Paris," said the 50-year-old lawyer. "I am very proud to be here. It is a way to say to Isil that the French people are here and you are not going to win."

The same spirit of determination was evident across the city yesterday.

As a banner outside one of the restaurants targeted in Friday night's attacks put it, in French: "Against extremism, Paris is united in life."

Yesterday morning, an 80-year-old woman ordered "my regular petit dejeuner" at a city centre café with her husband as they had done most weekends for the last 30 years.

"I have no fear," said Marie-Eve, a retired teacher, with a hint of a Gallic shrug.

Everywhere one walked, Parisians were reprising their routines. Such everyday interaction was carried out without any of the usual jollity: nobody laughed or smiled.

Most looked down at the ground or stared into middle distance, serious about doing whatever it is they usually do. Streets filled with people were eerily silent.

Outside Le Carillon restaurant, scene of one of the attacks, someone had turned the bullet holes that still scar the facade into a flower stand, threading a carnation through the glass.

No tape blocked the pavement in front, yet everyone stood a respectful five paces back, locals occasionally moving forward briefly to add a bouquet or a tea light to the hundreds already there.

Together with the five other attack sites, the restaurant formed a new pilgrimage route across the city as hundreds of Parisians retraced the terrorists' steps to these impromptu shrines, this time not with hatred but compassion.